1. Field of the Invention
The present invention relates to improvements in an exhaust system for a vehicle, and more particularly, to an exhaust system employing a spark arrester provided with a tail pipe and connected to the rear end of a muffler which is connected to an exhaust pipe in order to discharge exhaust gas from the muffler through the tail pipe of the spark arrester and into the atmosphere.
2. Description of the Background Art
A prior art exhaust system provided with a spark arrester for a motorcycle is disclosed in JP-A No. 8-61046. The exhaust system has a spark arrester incorporated into a muffler connected to an exhaust pipe, which is in turn connected to the exhaust port of an engine. A filter is included in the spark arrester which is inserted into an expansion chamber formed in the muffler to attenuate noise generated by the exhaust gas flowing through the muffler, and to arrest unburned components including soot or the like so that the unburned components may not be emitted into the atmosphere.
Usually this prior art exhaust system employs technical means for enhancing the suppression of exhaust noise, which divides the silencing chamber of the muffler into a plurality of expansion chambers, and connects the expansion chambers by restricting passages to deaden the exhaust noise by repeatedly expanding and compressing the exhaust gas while the exhaust gas is flowing through the expansion chambers and the restricting passages. However, additional parts including connecting pipes are necessary to divide the silencing chamber of the muffler into a plurality of expansion chambers and to connect the plurality of expansion chambers by restricting passages. Consequently, the division of the silencing chamber into the plurality of expansion chambers needs an increased number of parts, makes the construction of the exhaust system complicated and increases the cost of the exhaust system.